Energy Level Modulation of HOMO, LUMO, and Band-Gap in Conjugated Polymers for Organic Photovoltaic Applications (pages 439–445)
Bong-Gi Kim, Xiao Ma, Chelsea Chen, Yutaka Ie, Elizabeth W. Coir, Hossein Hashemi, Yoshio Aso, Peter F. Green, John Kieffer and Jinsang Kim
Article first published online: 14 SEP 2012 | DOI: 10.1002/adfm.201201385
A strong acceptor lowers both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of conjugated polymers (CPs), ultimately producing a narrowed band-gap. The energy level difference between the CP and the constituent monomers converge to a constant value, providing an energy level prediction tool. Organic photovoltaic performance is correlated with the CP's energy levels, and a 6.78% power conversion efficiency is achieved.